Nuclear Medicine, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
Radiology, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium.
BMC Cancer. 2018 Mar 5;18(1):253. doi: 10.1186/s12885-018-4154-7.
Gastro-intestinal stromal tumors (GISTs) are very rare tumors of the gastro-intestinal tract, originating from the interstitial cells of Cajal or a common cell precursor which both express type III tyrosine kinase receptors. Regorafenib is an oral multi-kinase inhibitor used to treat gastro-intestinal stromal tumors. To our knowledge this is the first case in literature to show the response of regorafenib on PET.
A 37-year-old male with lower abdominal pain and weight loss was referred to our hospital. Abdominal ultrasound and computed tomography (CT) showed diffuse peritoneal implants. Surgical specimen histology showed a GIST with c-KIT exon 11 deletion (c.1708_1728del) and treatment with imatinib 400 mg/day was initiated. Due to disease progression illustrated on baseline versus follow-up F-FDG-PET/CT scans therapy was switched to imatinib 800 mg/day and later to sunitinib 50 mg/day. Upon further disease progression 10 months later, third line treatment with regorafenib 160 mg/day was initiated. F-FDG-PET/CT showed the metabolic responses after 4 months regorafenib treatment ranging from complete response to the appearance of a new lesion in the liver. The new hypermetabolic lesion was only seen on the non-attenuation-corrected images because of breathing motion artifact.
This case illustrates that metabolic response can occur in GIST lesions without morphological response after third line regorafinib treatment. Furthermore this is the first case in literature to show regorafinib response on PET.
胃肠间质瘤（GIST）是一种非常罕见的胃肠道肿瘤，起源于 Cajal 间质细胞或共同的细胞前体，两者均表达 III 型酪氨酸激酶受体。瑞戈非尼是一种口服多激酶抑制剂，用于治疗胃肠间质瘤。据我们所知，这是文献中首例显示瑞戈非尼对 PET 有反应的病例。
一名 37 岁男性，因下腹疼痛和体重减轻就诊于我院。腹部超声和计算机断层扫描（CT）显示弥漫性腹膜种植。手术标本组织学显示 GIST 伴 c-KIT 外显子 11 缺失（c.1708_1728del），开始给予伊马替尼 400mg/天治疗。由于基线与随访 F-FDG-PET/CT 扫描显示疾病进展，治疗方案改为伊马替尼 800mg/天，后改为舒尼替尼 50mg/天。10 个月后疾病进一步进展，开始三线治疗，给予瑞戈非尼 160mg/天。F-FDG-PET/CT 显示瑞戈非尼治疗 4 个月后的代谢反应范围从完全缓解到肝脏出现新病变。由于呼吸运动伪影，新的高代谢病变仅在非衰减校正图像上可见。
本例说明，三线瑞戈非尼治疗后，即使没有形态学反应，GIST 病变也可能出现代谢反应。此外，这是文献中首例显示瑞戈非尼对 PET 有反应的病例。
